Figure 1 shows the DME placed in the e-box and situated on the left side of the engine compartment.
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instructions for removing the engine control unit (CAS removal down below)
Under the hood, on the passenger side’s exterior, is where you’ll find the Engine Control unit (DME/ECU). Locate the two plug DME/ECU, then release everything. Release both sideways-plugged plugs after moving the DME or ECU into the upwards position. (See Picture & Instructions Below)
1. Take off the air conditioning filter cover on the driver’s side. Right in front of the firewall is a triangular box that serves as the air conditioning filter cover. It is secured in place with three 8mm hex screws. Three screws are positioned: two at the top corners, one at the bottom.
- A. Take out the three screws that are securing the air filter cover.
- B. The air temperature sensor will still be holding the filter cover in place after it has been removed. Simply rotate the filter cover out of the way while keeping the sensor attached, leaving the master cylinder brake reservoir exposed.
2. Take off the air conditioning filter cover on the passenger side. The three 8mm-hex screws that secure the driver’s side filter cover to the filter cover on the passenger’s side are identical in size and shape.
- B. An air temperature sensor keeps the filter cover in place even after it has been removed. We’ll get rid of this sensor.
- C. A rotating lock fixture and two compression tabs support the air temperature sensor. Remove the sensor by rotating it until it releases. After that, remove the two compression tabs keeping the wiring in place by following the wiring. These compression tabs might need to be gently pricked in order to be removed. The ECU is housed in the white box beneath. The compression tabs should not be removed by pulling on the wiring.
3. Take out the gutter tray. The two air conditioning filter covers that were removed in (1) and (2) above are positioned underneath this tray. The tray fills the engine compartment’s entire width. Two machine screws with an 8mm hex head secure the tray.
- A. Take out the two machine screws that are holding the gutter tray in place.
- B. Take off the tray’s four rubber tabs that are keeping it in place.
- C. Take away the tray. Slides will release the tray. The engine hood struts could be struck. Simply move the tray around until it is completely gone. The ECU is located in the white box beneath this tray on the passenger side.
4.Take off the top for the white ECU compartment. Four locking tabs and two sliding locks secure this cover.
- A. Icons on the white ECU compartment cover designate the locked and unlocked states of these two sliders. To unlock the symbol, slide the two locks in that direction.
- The four locking tabs should be released. Each tab must be pulled outward from its corner until it unlatches by extending your arm beneath the ECU cover. To relieve pressure on the locking tabs, it is advisable to use two hands: one to draw the tab outward and the other to lift the locking tab bar upward. The location of the locking tab bar is supposed to be depicted in the images, not how to unlock them.
- C. Open up the ECU compartment by removing the cover.
5. Remove the wiring harnesses for the ECU. A sliding lock secures each ECU wiring harness in place. The wiring harnesses should be removed by pulling each sliding lock.
6. Take away the ECU. Two plastic tabs keep the ECU in place. Pull the ECU out by prying these tabs loose.
Location of the EWS from 1997 to 2001
1. Start by removing the push retention clips from the cover for the area just above the gas and brake pedals. The three Phillips screws are then removed.
2. Next, take off the two wood trims that are attached to the steering wheel’s sides. The electrical connector must also be unplugged.
3. Take off the cover that is just beneath the steering wheel. There are 7 Phillips screws holding it in. The leather component of that cover should then be carefully unclipped from the steering wheel using a flat-bladed screwdriver. It will be necessary to shift the parking brake release lever to the left and unhook it while firmly keeping the parking brake release lever in place. The lid will become entirely loose after doing this, allowing for removal.
4. Directly beneath the steering column is where you’ll find the EWS module. Two Phillips screws hold the module in place. To remove it, you’ll need a little Phillips screwdriver.
Please look at the photos below; they will assist you in removing your EWS unit.
What does DME mean for a BMW car?
One of the frequent issues with the systems in BMW vehicles is DME failures. However, BMWs are regarded as one of the top luxury antique automobiles in the world.
All significant engine activities are managed by a control system called Digital Motor Electronics (DME). The DME system helps the car’s engine run at peak efficiency with less reliability. Lower pollutants and fuel consumption are, however, the finest outcomes of DME.
Electronic devices eventually fail, as is clear. BMW DME is an electronic device, so it occasionally has problems and malfunctions. When the DME malfunctions, the vehicle will operate strangely, and the driver might not realize what’s wrong until it’s too late. How then can you determine whether problems with your BMW car are due to a defective DME?
What signs of BMW DME failure are there? If you notice any of the following symptoms with your automobile, a failed DME is likely to be the cause: poor engine performance, misfiring or stalling of the engine, inability to start the vehicle, illumination of the check-engine light, and increased emissions.
How is a BMW DME flashed?
2. Connect your automobile and Windows laptop with your D-CAN FTDI cable.
3. Set the second position on your automobile key.
Launch BMWFlash.
5. To install FTDI Drivers, click YES.
6. This window with the green bar should appear if your cable is connected in and ready to read the ECU.
*Note: If you purchased the cable we advised, it should have the designation FT232R rather than D-CAN.
Seven. Choose File > Read DME.
8. Click YES to download the whole contents of the ROM. This file will function as a backup file if problems arise in the future for any reason, therefore save a duplicate of it somewhere secure on your computer. It will take a while to read this; roughly 15-20 minutes.
9. BMWFlash now starts to read your ECU.
10. Rename using the structure shown here: Full Name-Base-Vehicle Year File saving.
How is DME represented?
Both ground-based and in-flight equipment are needed for distance measuring equipment (DME). DME equipment is typically located alongside a VOR or ILS/LOC. Like VOR and ILS systems, NAVAIDs use VHF to deliver their navigational signals. DME, on the other hand, uses UHF for transmission. Standard VHF NAVAID frequencies and corresponding UHF DME frequencies have been matched by the FAA.
For instance, regardless of where the VOR is located, all VORs using 113.0 will use the same DME frequency. To prevent your receiver from being impaired by mixed frequencies, the FAA spacing out NAVAIDs.
By timing the gap between the “interrogation pulse” from the transmitter and the “reply pulse” from the receiver, DME radios calculate distance. Similar to how submarines map the ocean floor using sonar sounds that bounce off objects.
DME is expressed in nautical miles and is calculated using a concept known as “slant-range distance.” Due to the aircraft’s altitude, slant-range readings will always be longer than anticipated distances.
A DME transmitter, for instance, will read about 1 NM if an aircraft is flying directly overhead it at an altitude of 6,000 feet.
What is the average DME slant range inaccuracy for aircraft operations? According to the rule of them, slant range error is minimal if you are at least 1 NM from the station for every 1,000′ AGL.
Therefore, your DME readout will be accurate if you are at least 5NM distant from the DME station and flying at 5,000′ above it (AGL).
Line-of-sight between the aircraft and the ground station is necessary for DME to function, and terrain and distance beyond the horizon will interfere.
The capacity of ground-based DME transmitters is also about 100 airplanes at a time. The equipment may not be able to pick up DME signals at all if there are too many planes using it.
Define DME sensor.
All components and conditions influencing the engine’s operation are picked up by the DME sensors. The analyzed data is subsequently converted into instructions for the fuel injection and ignition systems. Air flow rate, air density, air temperature, vehicle speed, and accelerator and throttle position are just a few of the more than 1,000 data points it gets per second. It checks the incoming data for accuracy and contrasts it with how the rest of the system responds.
If the sensor is broken, inaccurate data is given, and the DME substitutes the incorrect data with a predetermined, acceptable value. To prevent harm to the engine, DME will halt the supply of fuel to this cylinder if the spark plug in the Volkswagen is faulty or breaks. You may experience that when accelerating because this can alter how much power your engine produces.
The Volkswagen’s electrical system is also managed by the DME. The sensors are used to monitor the battery’s charge and power usage. It ensures long battery life by inspecting the battery cells, allowing the engine to start easily when needed.
What is controlled by the DME?
An electronic control unit (ECU), often known as a control unit or control module in the context of automotive electronics, is an embedded system that manages one or more of the electrical subsystems in a vehicle. Up to 70 ECUs can be found in certain current autos, including:
- engine management system
- likewise known as a powertrain control module (PCM)
- TCU: Transmission Control Unit
- TCU: Telephone Control Unit
- “Man-Machine Interface”
- Control Unit for Doors
- Seat Adjustment Device
- Environment Control Unit
- Unit for Speed Control
A microprocessor-based system called Digital Motor Electronics (DME) manages a number of auxiliary tasks of a car, including the ignition, fuel injection, oxygen sensor, and other components. An on-board computer utilizes an alphanumeric display to show you information such as the average fuel consumption, the driving distance possible with the fuel in the tank, the average speed, the outside temperature, etc. The DME gives raw data to the computer.
DME is sometimes referred to in the automobile industry as the Engine Control Unit (ECU), which falls under the category of Electronic Engine Management Systems.
DME works by continuously tracking variables like altitude, engine speed, intake airflow, exhaust gas composition, and engine temperature. In order to provide the engine the best performance and economy, DME may fine-tune it hundreds of times per second. In the event of specific electrical failures, DME features a fail-safe program. On-board diagnostics are also present in modern DME versions (OBD).
DME’s two basic functions are to inject the right amount of fuel and to provide a spark at the right moment. The system needs knowledge of the engine’s present condition to make this happen. DME can track dozens of various sensors, but every system must understand three fundamental concepts:
- the volume of air entering the engine.
- the throttle’s location.
- how quickly the engine is operating.
DME employs a fuel map to calculate how long each injector should remain open each cycle in order to inject the proper amount of fuel. It does this by using data on how much air is going through the engine and how quickly it is turning. The oxygen sensor, a device that sits in the exhaust collector and measures how much oxygen is still present in the exhaust, provides readings that are used to adjust the injector pulse-width during part-throttle operation. Under almost all circumstances, each cylinder is continuously modified for maximum operating efficiency.
DME has the ability to diagnose and reconfigure itself in the event of an electrical issue, allowing for speedy and effective troubleshooting.
Now Carlos, that’s a very thorough response and ought to hopefully get you started on the path to a better understanding. I am aware that it benefited me. There will be other responses to Carlo’s query as well as others. Please feel free to ask any questions and don’t forget to read the original post.